DORMOUSE: Detection Of Reflected Microscopic Optical UltraSound Emission

Aim of the PhD Project:

Investigate a new method for mapping ultrasound waves using light
Build a system to perform stand-off high-resolution ultrasound detection
Demonstrate imaging of a live subject based on this newly-developed technology

Project Description
Any science fiction fan knows the power of high-resolution whole-body imaging; a patient on a hospital bed is probed by unseen sensors, producing a virtual reconstruction of their body, which hovers over the bed, being manipulated, investigated and examined by the doctor. While existing whole-body imaging methods like CT, MRI, PET and SPECT can get some way towards this ideal, we still lack a truly whole-body imaging technique that is fast, high-resolution, non-invasive and safe for long-term monitoring.

Ultrasound imaging is the best technology for reaching this whole-body imaging ideal; it is non-invasive, can resolve features as small as 100 micrometres, and has extremely high data throughput. Nevertheless, it has traditionally been limited by the lack of high-resolution acoustic transmitters and receivers. Unlike cameras, which can record data with hundreds of megapixels of resolution, ultrasound transducers are limited to a few thousand pixels at most, and usually fewer than one hundred. Furthermore, ultrasound transducers must remain in contact with the patient, since ultrasound doesn't travel through air efficiently. The dream of creating a whole-body scanner requires a means of bridging this air-gap, and with a megapixel-resolution transducer array.

Fortunately for us, light is transmitted through air efficiently, and can be used to image acoustic waves. Furthermore, light can be patterned with megapixel resolution, sufficient to image a large fraction of an adult human body quickly, provided there is a way to turn the laser signal into an acoustic one and back again. In this project, a new type of approach will be developed, based on imaging the light in an optical fiber. This light changes when a sound wave passes, which is what allows us to detect the optical signal. An image of the proposed instrument in operation can be seen in the Figure.

The student will be part of a large ongoing collaboration to develop high-resolution optical ultrasound systems. They will be responsible for developing a fast ultrasound detector that can be scaled to large numbers of pixels (based on a silicon photomultiplier array and digital capture card) and using it to prototype a system that can image an acoustic field. The project will then progress to creating a small example instrument which can detect ultrasound at a range of several meters, with an initial resolution of 4X4 pixels, but which can be scaled arbitrarily just by adding more detectors.

Strains on the healthcare system in the UK create an acute need for finding more effective, efficient, safe, and accurate non-invasive imaging solutions for clinical decision-making, both in terms of diagnosis and prognosis, and to reduce unnecessary treatment procedures and associated costs. Medical imaging is currently undergoing a step-change facilitated through the advent of artificial intelligence (AI) techniques, in particular deep learning and statistical machine learning, the development of targeted molecular imaging probes and novel "push-button" imaging techniques. There is also the availability of low-cost imaging solutions, creating unique opportunities to improve sensitivity and specificity of treatment options leading to better patient outcome, improved clinical workflow and healthcare economics. However, a skills gap exists between these disciplines which this CDT is aiming to fill.

Consistent with our vision for the CDT in Smart Medical Imaging to train the next generation of medical imaging scientists, we will engage with the key beneficiaries of the CDT: (1) PhD students & their supervisors; (2) patient groups & their carers; (3) clinicians & healthcare providers; (4) healthcare industries; and (5) the general public. We have identified the following areas of impact resulting from the operation of the CDT.

- Academic Impact: The proposed multidisciplinary training and skills development are designed to lead to an appreciation of clinical translation of technology and generating pathways to impact in the healthcare system. Impact will be measured in terms of our students' generation of knowledge, such as their research outputs, conference presentations, awards, software, patents, as well as successful career destinations to a wide range of sectors; as well as newly stimulated academic collaborations, and the positive effect these will have on their supervisors, their career progression and added value to their research group, and the universities as a whole in attracting new academic talent at all career levels.

- Economic Impact: Our students will have high employability in a wide range of sectors thanks to their broad interdisciplinary training, transferable skills sets and exposure to industry, international labs, and the hospital environment. Healthcare providers (e.g. the NHS) will gain access to new technologies that are more precise and cost-efficient, reducing patient treatment and monitoring costs. Relevant healthcare industries (from major companies to SMEs) will benefit and ultimately profit from collaborative research with high emphasis on clinical translation and validation, and from a unique cohort of newly skilled and multidisciplinary researchers who value and understand the role of industry in developing and applying novel imaging technologies to the entire patient pathway.

- Societal Impact: Patients and their professional carers will be the ultimate beneficiaries of the new imaging technologies created by our students, and by the emerging cohort of graduated medical imaging scientists and engineers who will have a strong emphasis on patient healthcare. This will have significant societal impact in terms of health and quality of life. Clinicians will benefit from new technologies aimed at enabling more robust, accurate, and precise diagnoses, treatment and follow-up monitoring. The general public will benefit from learning about new, cutting-edge medical imaging technology, and new talent will be drawn into STEM(M) professions as a consequence, further filling the current skills gap between healthcare provision and engineering.

We have developed detailed pathways to impact activities, coordinated by a dedicated Impact & Engagement Manager, that include impact training provision, translational activities with clinicians and patient groups, industry cooperation and entrepreneurship training, international collaboration and networks, and engagement with the General Public.